1. Field of the Invention
The present invention relates to an image forming apparatus for forming an image on a sheet by an electrophotographic process, particularly to an image forming apparatus incorporating a plurality of air flow paths.
2. Description of the Related Art
The image forming apparatus based on electrophotographic process is provided with a passage for guiding the cooling air for cooling a fixing apparatus and development apparatus, the air including the ozone generated in a charging apparatus, and the air containing scattered toner, to ensure that the air, processed with dust protection and ozone elimination measures, is discharged out of the image forming apparatus.
Means are devised to ensure that cooling and ozone elimination steps can be taken effectively even when the apparatus is designed in a compact configuration and various forms of components inside the apparatus are packed in compact arrangements.
For example, the Japanese Unexamined Patent Application Publication No. 10-115958 (JPA10-115958) discloses an image forming apparatus wherein a ventilation duct is installed between the cleaning apparatus and fixing apparatus and an outer air intake fan is arranged in the vicinity of the charging apparatus. The incoming air is led in the axial direction of the aforementioned photoreceptor inwardly (one way only), and is then led in the axial direction of the aforementioned photoreceptor inside the aforementioned ventilation duct outwardly to be discharged out of the image forming apparatus.
In the image forming apparatus of JPA10-115958, the direction of air flowing in the vicinity of the charging apparatus is opposite that of the air flowing through the ventilation duct between the cleaning apparatus and fixing apparatus.
Such an airflow path cannot be said to be a rational and effective flow path in an image forming apparatus of compact configuration.
To be more specific, air flows through the image forming apparatus in two opposite directions. If two air paths are arranged close to each other in a compact version, two streams of air flowing in opposite directions will interfere with each other. Thus, one air stream will hinder the other air stream, with the result that the effects of cooling, ozone elimination and scattered toner recovery may be reduced.
To solve this problem, the air flow paths must be separated from each other. This will make it difficult to design a compact apparatus.
Several types of air flow paths arranged around the development apparatus in particular are close to one another, and there will be serious interference among flow paths.
The object of the present invention is to solve such a problem and to provide an image forming apparatus of compact design wherein sufficient ozone elimination, recovery of scattered toner and cooling of development apparatus are ensured.